This invention relates to means for sensing the value of a coin in a parking meter and for moving the time indicator across the time scale a distance corresponding to the value of the coin being cycled through the meter. It is conventional in prior art meters to sense the value of the coin by sensing its diameter. However, in prior art multiple coin meters a problem is encountered when it is desired to handle a series of coins in which the diameters of the coin do not serially correspond to the values of the respective coins, such as for example in the series composed for a penny, nickel, dime or nickel, dime, quarter. In order to overcome this problem it has been necessary in prior art meters to resort to relatively complex mechanisms such as that shown for example in U.S. Pat. No. 2,901,078. In such devices the accuracy of the sensing device is critical and may be subject to malfunction. Also in prior art meters such as that disclosed in U.S. Pat. No. 2,901,078 if a spurious coin of a size intermediate of the size of any two successive coins of a series it is designed to accommodate, is inserted in the meter, the meter will register the value of the next largest coin it is designed to accept and therefore an amount of time may then be registered which is beyond the value of the spurious coin.
Another approach to this problem is suggested in U.S. Pat. No. 3,126,995 to Kissinger et al. In the mechanism disclosed therein, a relatively large control disc having a series of slots each of the length corresponding to the value of the coins to be accepted by the meter is positioned in accordance with the size of the coin being cycled, to locate one of the slots in alignment with a pin. The pin is then free to move the length of the slot and in so doing move the indicator an appropriate amount corresponding to the value of the coin. The mechanism disclosed therein is also complex in that the member carrying the pin must be geared with the member carrying the indicator at a ratio to provide sufficient movement of the indicator to register the correct amount of the time by movement of the pin the distance permitted by the slot. Also the member containing the slots is relatively large and therefore requires a significant amount of force to position it in accordance with the diameter of the coin.
The invention herein overcomes these disadvantages by employing a simple, light-weight indexing arm to sense the value of the coin and which carries a pin which is located in alignment with an appropriate one of several grooves formed in the index disc, the groove being of proper length to allow movement of the disc and pointer an amount to register time corresponding to the value of the coin being cycled, through the meter.